The invention relates to a protection for glass fibers for telecommunication with hollow leads in distribution fields of cassette arrays in cable sleeves.
Up to now, glass fibers are generally fed into glass fiber cable bundle leads for splicing up to the commercial splicing cassettes and from there, are then fed further via the cables"" own bundle leads into the exiting cable. If however more glass fibers are fed into a bundle lead than are to be spliced within a splice cassette, these glass fibers must be correspondingly split, i.e. they have to be removed from the bundle lead and, as the case may be, be fed within other suitable protective tubes. In one such splitting, a splitting adapter to which, for example, the tubes are individually attached is commonly used. In another exemplary technique a corresponding number of tubes lead directly out of the cassette. It is however sensible to protect the glass fibers which are fed out of the cassettes or out of the bundle lead against mechanical influences.
It is also generally known to route glass fibers in thin tubes, or so-called hollow leads, in the distribution field. However, this requires varying diameters and varying lengths of hollow leads. In addition, the hollow leads must be attached on both sides of the cassettes as well as at the end of the cable. In this sense, cassettes comprising clamp grooves for holding individual hollow leads are known. This then requires the installer at the construction site to, for example, group hollow leads belonging together into bundles and to attach these with cable connectors to the respective appropriate cassette. This procedure, however, entails a high degree of effort during assembly, since the hollow leads must first be cut to length from a supply roll, layed and individually attached. This is the general prior as it is currently applied in distribution fields.
The goal of the present invention is to provide a protection for glass fibers for telecommunication with which the degree of assembly complexity in making the distribution fields can be reduced. The posed goal is met with a protection for glass fibers for telecommunication with hollow leads of the type mentioned at the outset, in which multiple hollow leads are gathered together lengthwise to a composite element at at least their first ends, and in which the ends of the hollow leads can be individually cut off to the required length.
The embodiments according to the invention for the protection of glass fibers for telecommunication result in considerable work for the assembler, since connection elements which have already been gather for him are provided, which, as the case may be, are also individually cut to the required lengths. Gathering the individual hollow leads also results in a considerable simplification during the fixing of these composite elements since they can exit from a splitting point and can then be easily routed to the corresponding distribution points. These composite elements of gathered individual hollow leads can be designed as a round bundle or as a flat band. The composite or the gathering of the individual hollow leads can extend over the entire length required so that a continual composite exists. The assembler then opens the individual hollow leads at the end point or close to the end point of the composite, so that the hollow leads are routed starting from the opening point individually, for example, to different cassettes. Such a composite element can either be offered in endless form or can be cut to a particular length. However, according to the invention, composite elements are also provided in which the individual hollow leads are held together only at one point or discontinuously at multiple points with connection pieces or by gluing. For a given distributor sleeve, it is therefore basically possible to provide a composite element system exactly tailored to the laying requirements. For the assembler, a ready-made composite element system of this sort results in a considerable savings in assembly time, since the cutting to size, laying and fixing of individual hollow leads is eliminated.
The connection of the individual hollow leads along the surface lines can for example be accomplished by melting the outer covering layer followed by compression. Mutual gluing with thermal glues or with UV-curing glues, two-component glues or instant glues is also possible, wherein not only a discontinuous, but also a continuous composite can be produced. By co-extruding multiple hollow leads, it is possible even here to produce a corresponding composite.
A special material combination is required in the hollow leads suitable for such an application. A hard but elastic plastic such as for example polycarbonate (PC) in the inner area of the hollow lead is especially suitable for this, so that the hollow lead does not crimp and possibly damage the glass fibers. In the outer area, a soft, weakly adhesive layer, for example made of polyurethane, is applied by which the mutual adhesion of the hollow leads is enhanced.